The invention generally relates to digital X-ray detector panels.
The use of digital radiological imaging continues to be invaluable with respect to a variety of technical applications. Digital radiological imaging is a mainstay in the medical field allowing health care professionals to quickly discern and diagnose internal abnormalities of their patients. Additionally, its use has become increasingly important in industrial fields for visualizing internal contents of parts, baggage, parcels, and other objects, and for visualizing the structural integrity of objects and other purposes. Indeed, the evolution of digital X-ray detectors has enhanced both workflow and image quality in the field of radiological imaging.
Generally, radiological imaging involves the generation of X-rays that are directed toward an object of interest. The X-rays pass through and around the object and then impact an X-ray film, X-ray cassette, or digital X-ray detector. In the context of the digital X-ray detector, these X-ray photons traverse a scintillator that converts the X-ray photons to visible light, or optical photons. The optical photons then collide with the photodetectors of a digital X-ray receptor and are converted to electrical signals which are then processed as digital images that can be readily viewed, stored, and/or transmitted electronically.
It is a common practice in the X-ray detector industry to tile multiple photodetector panels together into a larger panel because either a single panel is not large enough or is too expensive. In the case of a complementary metal-oxide semiconductor (CMOS) based X-ray detector, for instance, a single 20 centimeter by 20 centimeter squared detector panel would require using a 30 centimeter wafer, which is much more expensive than tiling 20 centimeter wafers due to both the low yield of the larger panel as well as the expensive equipment of the larger wafer. In the existing technology, the X-ray scintillator such as CsI is deposited on a fiber optic plate (FOP) and sealed with a scintillator cover. The obtained scintillator assembly is then attached onto the tiled CMOS panel, which not only degrades the performance of the scintillator but also add significant cost to the product since the FOP is very expensive.